Agents who represent themselves.
Every once in a while you see this from legitimate agents, and it drives me up the wall. An agent sends us a manuscript they've written, on their agency letterhead, with a cover letter with all the normal schmoozing. And we're expected to treat that manuscript as agented?
Certainly in the strictest sense, it is agented. But publishers offer agented manuscripts faster turnaround and more personal responses because agents are supposed to be doing some of the slush-sifting for us. That doesn't actually apply when it comes to something they wrote.
So I'm wracking my brain for a professional, polite way of saying, "You can't be trusted to be impartial or discerning about your own writing. Your manuscript has gone into slush with all the other unsoliciteds."
But so far, no luck.